[StainlessS]

Removed script functions [ GreyRamp(), MyFunc() ], embed code directly into main level script.
Not much difference. (craps out about 1440 frames)

/*
    Req:
        Avs+
        SelectPixelByMask
        RT_Stats.
        requires OUT\ directory in current dir

        SelectPixelByMask(clip Data, clip Mask)
            Data    256 frames, Y8 or YV24, or RGB24, or RGB32.
            Mask    Y8
*/

# CONTRAST
StartCont = 0.5      # Mask 0
EndCont   = 2.0      # Mask 255
BaseName  = ".\OUT\MyPic_"
Matrix    = "Rec601"
myName    = "SelPix3: "
DEBUG     = True

###################
AviSource("D:\SELECTPIXELBYMASK\Parade.avi")
trim(60,0)                                        # trim off static start
BilinearResize(256,256)                           # Try not to swamp memory too much
ConvertToYV24()                                   # Sat will not work on Y8, And not RGB either (Tweak YUV only)
ORG=Last
FC=ORG.Framecount

Msg=MessageClip("Done")                           # Create now when mem avilable
###################
black = BlankClip(Length=1,color=$000000, width=1, height=256,Pixel_type="Y8")
white = BlankClip(Length=1,color=$ffffff, width=1, height=256,Pixel_type="Y8")
Mask=StackHorizontal(black,white).BilinearResize(512, 256).Crop(128,0,-128,-0).Loop(FC)

#Mask=Mask.BilinearResize(Width,Height)           # Rough ramp, single frame, same size as clip,  just for testing
#return Mask.info

BaseName=RT_GetFullPathName(BaseName)

StartTime=RT_TimerHP
For(n=0,FC-1) {
    current_frame=n
    Data=ORG.Trim(0,-1).Loop(256)       # 256 identical frames
    Data=Data.Animate (0, 255, "Tweak",
        \                          [* START Args          *]
        \ 0.0,                     [* Hue    default 0.0  *]
        \ 1.0,                     [* Sat    default 1.0  *]
        \ 0.0,                     [* Bright default 0.0  *]
        \ StartCont,               [* Cont   default 1.0  *]
        \ False,                   [* Coring Default True *]
        \                          [* END Args            *]
        \ 0.0,                     [* Hue    default 0.0  *]
        \ 1.0,                     [* Sat    default 1.0  *]
        \ 0.0,                     [* Bright default 0.0  *]
        \ EndCont,                 [* Cont   default 1.0  *]
        \ False                    [* Coring Default True *]
        \ )
    Out=Data.SelectPixelByMask(Mask).Loop(FC)
    Out=Out.ConvertToRGB32(matrix=Matrix).ImageWriter(file=BaseName, start=n,end=n, type="png")
    Out.RT_AverageLuma(w=1,h=1)                # Force write image file
    if(DEBUG) {
        Tim = RT_TimerHP
        RT_DebugF("%d] %f%% %.2fFPS",n,(n+1)*100.0/FC,1/(Tim-StartTime),name=myName)
        StartTime=Tim
    }
    Out=0
    Data=0
}

Return Msg